# Graph-based Label Propagation for Semi-Supervised Speaker Identification

**Authors:** Long Chen, Venkatesh Ravichandran, Andreas Stolcke  
**arXiv:** [2106.08207](https://arxiv.org/abs/2106.08207)  
**Date:** 2021-06-15  
**Summary page:** https://www.summarizepaper.com/en/paper/2106.08207v1/

## Key points

- The paper addresses the challenge of speaker identification in the household scenario, specifically for smart speakers.
- Existing methods rely on a limited number of enrollment utterances and a larger set of unlabeled data.
- The authors propose a graph-based semi-supervised learning approach to improve speaker profiles.
- Unlike most existing works, this study emphasizes speaker label inference or scoring rather than speaker-discriminative embeddings.
- A pre-trained embedding extractor is used, and graph-based learning integrates information from labeled and unlabeled utterances.
- Utterances are considered as graph nodes, and pairwise utterance similarity scores are represented as edge weights.
- Graphs are constructed per household, and speaker identities are propagated to unlabeled nodes to optimize global consistency criterion.
- Experiments using the VoxCeleb dataset demonstrate that the proposed method effectively utilizes unlabeled data and improves speaker identification accuracy compared to two state-of-the-art scoring methods.
- The proposed method outperforms semi-supervised variants based on pseudo-labels.
- In conclusion, the paper presents a novel graph-based semi-supervised learning approach for speaker identification in the household scenario.

## Summary

The paper titled "Graph-based Label Propagation for Semi-Supervised Speaker Identification" by Long Chen, Venkatesh Ravichandran, and Andreas Stolcke addresses the challenge of speaker identification in the household scenario, specifically for smart speakers. The existing methods for speaker identification in this context rely on a limited number of enrollment utterances and a larger set of unlabeled data. To improve speaker profiles, the authors propose a graph-based semi-supervised learning approach that leverages the unlabeled speech samples. Unlike most existing works in speaker recognition that focus on speaker-discriminative embeddings, this study emphasizes speaker label inference or scoring. The authors utilize a pre-trained embedding extractor and employ graph-based learning to integrate information from both labeled and unlabeled utterances. Each utterance is considered as a graph node, and pairwise utterance similarity scores are represented as edge weights. Graphs are constructed per household, and the identities of speakers are propagated to unlabeled nodes to optimize a global consistency criterion. To evaluate the effectiveness of their approach, experiments were conducted using the VoxCeleb dataset. The results demonstrate that the proposed method effectively utilizes unlabeled data and improves speaker identification accuracy compared to two state-of-the-art scoring methods. Furthermore, it outperforms their semi-supervised variants based on pseudo-labels. In conclusion, this paper presents a novel graph-based semi-supervised learning approach for speaker identification in the household scenario. By leveraging unlabeled data and optimizing global consistency criteria through label propagation on graphs constructed per household, the proposed method achieves improved accuracy compared to existing approaches.